In their overview by John Protzko, Joshua Aronson and Clancy Blair they’ve collected research on the different elements that could have an influence on the intelligence of children. For a study to be included it had to be a randomized controlled trial (RCT). In their research they also focused specifically on IQ and associated tests of intelligence. This means more general conceptions of intelligence weren’t considered. In t the resulting paper they than analyzed 70 studies to better understand what does — and what doesn’t — boost a young child’s IQ.

Let’s take a look at the results:

• When it comes to nutrition, there’s not much evidence that multivitamins do any good, but having pregnant and lactating moms and young kids take Omega-3 fatty acid supplements (particularly DHA) likely does.
• Just having books in the home might not help, but interactive reading with children under 4 could boost IQ by around 6 points.
• Enrolling children in early educational interventions does work
• Also sending children to preschool does have a positive influence.

Abstract of the research:

Can interventions meaningfully increase intelligence? If so, how? The Database of Raising Intelligence is a continuously updated compendium of randomized controlled trials that were designed to increase intelligence. In this article, the authors examine nearly every available intervention involving children from birth to kindergarten, using meta-analytic procedures when more than 3 studies tested similar methods and reviewing interventions when too few were available for meta-analysis. This yielded 4 meta-analyses on the effects of dietary supplementation to pregnant mothers and neonates, early educational interventions, interactive reading, and sending a child to preschool. All 4 meta-analyses yielded significant results: Supplementing infants with long-chain polyunsaturated fatty acids, enrolling children in early educational interventions, reading to children in an interactive manner, and sending children to preschool all raise the intelligence of young children.